EvolutionMarch 1, 1949
The Ancestors of Mammals
In the Permian and Triassic Periods lived the therapsids and the ictidosaurs, a curious group of reptiles with many mammalian characteristics
Stories by Edwin H. Colbert
The Ancestors of Mammals
In the Permian and Triassic Periods lived the therapsids and the ictidosaurs, a curious group of reptiles with many mammalian characteristics